Nowadays, controlling water pollution is a subject of research by environmental protection personnel, and water pollution is one of the serious crises that facing human today. Controlling water pollution, especially controlling toxic and harmful organic pollution in water, is a key point and a difficult point in water treatment engineering research. In recent years, use of advanced oxidation technologies (AOTs) activating a persulfate (PS) to generate sulfate radical anion in treatment of refractory organic wastewater is a research hotspot in the technical field of wastewater treatment.
Compared with the traditional Fenton method, the PS oxidation technology produces SO431  without requiring an acidic condition of pH 3-5to achieve an effective degradation of pollutants, and SO4− has a standard oxidation-reduction potential (E0=+2.5 to +3.1 v) higher than a hydroxyl radical (OH.) (E0=+1.9 to +2.7 v) generated by the Fenton method, a higher stability, a longer half-life period (about 4 s), and a lower reactivity with background organics naturally occurring in the wastewater. Thus, the PS oxidation technology has a higher efficiency in oxidative degradation of pollutants. In existing reports, photoactivation, thermal activation, ultrasound and metal ion activation are generally used for formation of sulfate radical anion from the persulfate. However, these technologies have disadvantages of high cost, sludge generation and the like, which make them difficult to be widely used in real life. Use of a metal organic framework as a heterogeneous catalyst to catalyze the persulfate or a hydrogen persulfate to produce sulfate ions overcomes these disadvantages, has advantages such as reusability, high activity, and good catalytic effect, and has become a research hotspot for researchers today.
Metal organic frameworks (MOFs) are a kind of crystalline porous materials with a regular pore or hole structure obtained by coordination self-assembly of metal nodes and organic ligands. This material has a relatively high specific surface area, a rich pore structure and a relatively high physical and chemical stability, and is easy to load other substances without changing its own structure, and the metal organic framework contains a large number of unsaturated coordination metal nodes, making it shows excellent performance in aspects such as catalysis, separation, and adsorption. At present, researches of MOFs in the field of AOTs have made preliminary progress. For example, MIL-88A was successfully applied to activate PS for oxidation degradation of rhodamine B dye and gold orange G dye (RSC Advances. 2015, 5: 32520-32530; RSC Advances. 2016, 6:112502-112511); MIL-100 (Fe) and [Cu2(btec)(btx)1.5]n, were proved to be effective catalysts for a Fenton-like reaction, and were capable of activating H2O2 degradation to produce OH. (Journal of Molecular Catalysis A: Chemical. 2015, 400: 81-89; Cryst. Eng. Comm. 2012, 14: 4210-4216); and a research found that ZIF-67 and Co3(BTC)2.12 H2O are both high-efficient heterogeneous catalysts for catalytic activation of peroxymonosulfate (PMS) (Journal of the Taiwan Institute of Chemical Engineers. 2015, 53: 40-45; Journal of Hazardous Materials. 2016, 318:154-163).
In the present invention, a catalytic material MIL-88A@MIP which is synthesized using a metal organic framework as a precursor and has a selectivity for degradation of a papermaking wastewater combines the advantages of the metal organic framework, and the material is further modified using a molecular imprinting method. That is, MIL-88A@MIP means that MIL-88A is coated with a molecular imprinted polymer (MIP) on the surface thereof. The catalytic material thus enables a high-efficient catalytic activation of the persulfate to produce sulfate radical anion that selectively adsorbs and degrades organic pollutants, especially phthalates, in the papermaking wastewater. The catalyst has a good recycling effect, an operation cost is reduced, and its pH application range is wide, providing a wide range of application prospects for the treatment of the papermaking wastewater.